Is Ted Cruz considered a ‘natural born citizen?’ An explainer

Donald Trump thinks Ted Cruz's Canadian birth could be a "big problem" if it leaves the judicial system trying to decide Cruz's eligibility to be President — but some experts say there’s no question he is a natural citizen.

The courts have never directly addressed the definition of being a natural-born citizen, and the Constitution does not fully explain the requirements.

The U.S. State Department addresses the issue of citizenship at birth by saying "a child born abroad to one U.S. citizen parent and one alien parent acquires U.S. citizenship at birth under Section 301(g) of the Immigaration and Nationality Act."

It requires that one of Cruz's parents lived in the United States for at least 10 years with five of those years coming after the age of 14. Cruz's mother, Eleanor Darragh, fits this demand.

The closest the Supreme Court came to addressing the issue is when it ruled in 1971 with Rogers v. Bellei that a person born to an American parent outside the U.S. and granted citizenship at birth can have that citizenship revoked if he or she doesn’t fulfill the residency requirements.

Donald Trump said Cruz's citizenship could be a "big problem" for the GOP.

(John Locher/AP)

The key statute of the order — which led to Aldo Maro Bellei, who was born in Italy to an American mother, to lose his citizenship — is that the citizen must live in the U.S. for five years between the ages of 14 and 28.

Former Solicitors General Neal Katyal and Paul Clement looked at the question of Cruz’s citizenship last March and discussed it in an article for the Harvard Law Review.

"Despite the happenstance of a birth across the border, there is no question that Senator Cruz has been a citizen from birth and is thus a 'natural born Citizen' within the meaning of the Constitution," the piece says.

It's difficult to presume exactly what the Founding Fathers intended when they wrote “natural-born.”

Despite being born in Canada, some experts say their is "no question" at Cruz's eligibility to be President.

(MARK KAUZLARICH/REUTERS)

Did Alexander Hamilton, a native of the British West Indies, want it to mean persons born only in America?

John Jay was a proponent of "natural birth" out of concern that someone in the executive office could swear allegiance to another government.

But Senator Cruz renounced his Canadian citizenship in 2014 — which required him to submit a formal document to the Canadian government.

Still, Senator Cruz is far from the first person to have the location of his birth brought into question when running for the presidency.

At least 10 candidates — including John McCain, who was born in the Panama Canal Zone, and George Romney, who was born in a Mormon enclave in Mexico — have been questioned for their eligibility.